Duck! wrote:
It's passable if your riding doesn't require a huge gear range, but start mixing up the terrain its compromises become very apparent. If you want a big gear range, you'll end up with big jumps between ratios. More sprockets help close the gaps, but upgrading to suit brings considerable expense, and still doesn't address every problem.
You can change chainrings to suit different overall profiles, but then you have the problem that picking a smaller ring to shift the focus to climbing comes at the expense of top-end for the descents that follow, or going a bit bigger on the chainring to help the top end a bit will mean the climbs hurt more. Or you can pick something in the middle that will hurt both top and bottom end gears....
I feel like I've done this before, but anyway... I've got well over 20,000km on my 1x road setup now so I think I'm in a pretty good place to talk about it. These are fair points, but I think people overestimate how much impact they actually have in the real world. I think the takeaway is that it's just not that different, you get used to it like anything else, but that there's not much point getting used to it unless it offers you some actual advantages (which for most people it doesn't).
Range? 52t + 11-42 gives better range than 52/36 + 11-28. Based on how many compact cranks I see about lots of people are surviving with 50x11 or 50x12 as their lowest so for most I don't see how it would be a problem
Spread? Comparing the common 11-28 and the 11-42 we have:
11-13-15-17-19-21-24-28-32-37-42
11-12-13-14-15-17-19-21-23-25-28
This is the big compromise on paper I think. The most significant hole I used to notice was the 12t when I only had a 50t ring, but after a few hundred kilometres I was over it. My legs just got used to it. I think if you were doing a lot of climbing, like regularly doing 30min+ climbs, you'd notice the 5t jumps in an 11-42 right at the top but the worst of my commute is about 10 minutes at 5% with a short pinch at 8% so I don't get bothered by it. Outside of that, it's just something you get used to and it's imperceptible after a while.
In terms of real world utility, there's just not a lot lost most of the time, but there's nothing really gained either. You have the spread of a regular drivetrain, you just have bigger holes that you've stopped noticing because you're used to it so in the end it's a wash.
These are very minor pluses: When I do maintenance I only have 1 gear cable to replace. I have 1 less cable around my front bars. I don't have to tune a front derr or worry about it rubbing or anything. Shifting up and down 1 cassette and not thinking about cross-chaining is nice for me. For a bike that cops ~450km a week in all weather these are all solid pluses - a few things less to worry about wearing out or breaking and having to fix on the side of the road, or on a weeknight when I'm tired. In terms of weight, nothing is saved - lose a gear cable, lose a ring, lose a derailleur... add a bigger cassette and a larger derailleur and 1x11 is almost certainly heavier.
The only 1x drawback I can come up with is the chainline in the lowest gear. The rear derr makes a bit more noise in 52-42, but that's about it, and TBH you don't spend that my time in a bail out gear unless it's proper steep. It's not draggy in the 52-42, I still get 2000-2500km per chain, exactly like my other bikes so it's not adding to wear. I haven't broken a chain yet so AFAIK it's not weakening them.
Would I take it racing? For crits, yes. My regular crit bike has a 52t front ring with 11-25 out the back and i spend almost all my races somewhere between the 12 and the 17 so range isn't an issue and I can deal with the gaps. For a roadrace with actual hills, no because gaps will be super annoying if you're on the redline climbing for instance...
Probably the only other time I wouldn't want it is on a proper hilly ride, like the alpine classic or similiar. 5t jumps would certainly get irritating if you're climbing for an hour and you can't find rhythm with the gears that you've got.
So where do they sit in the real world? If you've got 2x11 there's almost no case for going 1x because the pros/cons are a wash. In my case, i did it as a new build from scratch knowing full well that I never used my small ring on the route I was going to ride daily with this bike. Maybe you'd buy one brand new off the shelf for something different? Honestly, I don't know who they're for, but I know they certainly work in practice a lot better than people think.
FWIW, most of the 1x MTB systems i see are strangely under-geared. If I'm climbing something that's so steep and technical that I need 30x50 then I may as well get off and walk before I fall over sideways, and that's at the expense of utility on the flats. For this reason, of my 2 MTBs, 1 runs a 42t front ring so that I can bomb along firetrails...